Facebook does a fantastic job of tapping into an innate human neuroticism: the desire to share and promote yourself among others.

It also taps into another innate part of human nature, but less so: grading. Users often "grade" their friends by how many friends they have on Facebook.

However, Facebook doesn't have a direct way for users to grade each other, or be graded.

If Facebook wants to tap into that component of human nature, it should buy Klout.

Yes, it sounds a little crazy, but it's not.

Here are three reasons it makes sense:

It will encourage people to share information more readily. The more information you share, the higher your score will be. Mark Zuckerberg has insisted that he wants users to share more information, because they can discover more that way.

It will keep them on the site longer. Love it or hate it, users neurotically check their Klout score. They will want to check their score more often to see how it has changed, which gives Facebook an opportunity to serve more ads. It can also target ads better by determining what its users are "influential" about, much like Klout does today.

Klout will add more incentives to connect to other services. Zuckerberg said he could see a future where all apps are connected to Facebook. This would accelerate that and, again, encourage users to share more information on the site.

It will add additional signals for filtering out noise. By determining what areas a user is "influential" in, Facebook would be able to deliver more relevant news feed items and recommend friends more accurately.

Don't take our word for it, though.

We spoke with Kendall Collins, who heads Salesforce's social networking tool, Chatter. It's an enterprise social network that has 150,000 customers and millions of users logging into the service on a daily basis.

On Chatter, individuals are graded on their "reverberation" and given an influence score. This means the more users interact on the service and communicate with other employees, the higher their influence.

More communication means better cooperation and a better-run business, so it's a tool geared toward promoting better communication. But by adding an "influence" component, it's given employees another incentive to communicate with one another, Collins said.

Companies have started rewarding the most influential employees at their companies by bringing them to executive meetings, and in return it's encouraged employees to become more active on the networks, Collins said.

That's something Klout can do for Facebook. Facebook can also monetize Klout by finding ways to connect brands with "influencers." That could provide an additional source of revenue for Facebook — which is showing some weakness in its advertising division.

Zuckerberg could just build a tool himself with a series of badges or grades, but it might even be easier at this point to flat out buy Klout and the talent that's at that company.